Wonderwall

Madonna, Sean Penn reunite at 'Secret Project' event

Still crazy for each other after all these years? Madonna's A-list friends turned up to support the pop legend, 55, at the screening and launch of her "Secret Project Revolution" film at the Gagosian Gallery in New York on Sept. 24 -- but none more noticeable than Sean Penn.

The former spouses, who divorced in 1989 after four years, have remained cordial, and Penn, 53, was on hand with the likes of Zachary Quinto, Anderson Cooper, Lindsay Lohan, Calvin Klein, Donna Karan, Zac Posen and Lee Daniels for the premiere of Madonna's short film project with Steven Klein.

The Oscar-winning actor was the first to arrive and greet his ex-wife, with the pair -- once known as the "Poison Penns" for their constant bickering -- obliging for a photo.

Although both the singer and actor moved on -- she married and divorced director Guy Ritchie, he did the same with Robin Wright -- the pair may still hold a candle for one another. Checking out his ex's Oct. 2012 MDNA concert in Los Angeles, Penn couldn't take his eyes off the "Hung Up" singer onstage, a witness told Us.

"Their chemistry was off the charts," a concert-goer raved. "Madonna seemed to be performing entirely for Sean. And he was saying things like 'Amazing!' and 'She's so hot!'"

"Madonna's friends wish she'd get back with Sean," another source has said of Madonna, now dating dancer Brahim Zaibat, 27. "He will always be the love of her life."

Before the "Secret Project" film was screened, Madonna, wearing her gold grills and a black, shiny trench coat with black lace gloves, addressed the small, elite crowd in a long monologue about the work.